FONTANA, Calif. — One driver described them as canyons. Another called them treacherous. Another said they were troublesome, but not any worse than last year.

Without question, though, Saturday's IndyCar season finale at Auto Club Speedway will be affected by the track's notorious seams.

"I don't think it's gotten any worse over the last 12 months, but certainly it's the biggest challenge of this race track," James Hinchcliffe told USA TODAY Sports after Friday's qualifying session. "It makes these cars very edgy to drive with the downforce levels we're running."

The seams are separations in the asphalt that run parallel to the cars. The feeling of changing lanes across the seams is akin to changing lanes from one surface to another in a road construction zone.

"They're terrible, man," said Marco Andretti, who qualified eighth-fastest but had the fastest lap in Friday's late practice session. "That's the character of this place, for sure. It can really catch you out. Cars are all over the place."

Drivers praised track officials for a grinding project that smoothed some harrowing bumps near the entry of Turn 3, but said the seams are still an issue.

"They're not great, but that's how Fontana is," Josef Newgarden said. "The bumps on the backstretch are much better. They did a nice job of grinding that down. It's a little more manageable, but you still have to battle the seams through the corner."

Two crashes during Friday's early practice session — involving Pippa Mann and Takuma Sato — were blamed on the seams. AJ Allmendinger, who encountered the same issue while finishing 16th in a NASCAR Sprint Cup race at the track in March, said the seams are exaggerated by the speed, downforce and lighter weight of Indy cars.

"It's the same issue," Allmendinger said. "You still try to run in between them and find that lane to run in through the corner and stay in that lane. The car itself moves around a lot more. In a way, there's a lot more room for error with speeds this high."

The two-mile oval hasn't been resurfaced since it opened in 1996. Some drivers are calling for it.

"It's one of two things — it's either resurfacing the track or we switch our downforce rules," Hinchcliffe said. "We're not in any rush to get back to pack racing, so realistically the only fix is resurfacing the track."